Los Angeles daily herald., 1887-02-06
Popular Water Tests.

holes through his hat and one in his
clothes
Popular Water Tests.
BY PROF. E. r.. ANGEL. o..
An easy and quite reliable test fci
orr sanic matter III water is this: Add
abont ten grains of pure grnaulated
sugar to about five ounces of the water
to be tested; the bottle should be com.
pletely filled, and the stopper tightly
fitted, SO as to exclude the air. Ex-
pose the water to daylight and tenn
perature of about seventy degrees Fahr.
enheit. If it contains much organic
matter, an abundance of whitish specks
will appear within day or two, Il oat.
ing around in the liquid. OF course
the more organic matter there is, the
more marked the appearance. These
little bodies are best observed by hold.
ing the bottle against something black,
or by partly shading the farther side
of it with the hand. After q while
they will group themselves together in
punches, and partly settle to the bot.
tom of the bottle; at length. if the
water is very bad, the odor of butyric
acid (the smell of rancid butter) becomes
percepti tible.
FOR AMMONIA.
Dissolve some mercuric chloride (cor.
rosive sublimate, poisou) in a little
water, making the solution quite strong.
Also prepare strong solution of carbon.
ate of soda common cooking soda will
do) by dissolving it in water. Place a
tumbler of clear glass on black surface
in good light; ill it with water TO be
test, and then add single drop of the
solution of mercuric chloride, followed
by drop of the soda solution in the
same place. Let the liquid stand with.
out stirring. Look down through it,
aud if ammonia is present, even q minute
quantity, a white cloud OF opalescencs,
r sembling white smoke, will be observed
toward the bottom of the glass where
the drops passed, which in some hours
will settle and cover the whole or part
OF the bottom ii the glass with u white
coating. II much ammonia is present,
the reaction will be very marked and
almost instantaneous. Less ammonia
requires more time, aud the reaction is
less marked. The delicaey of the test
is sufficient to give within five minute
a distinct reaction in water containing
.000O0l part of its weight of ammonia.
If water shows the reaction, it is far
from the sanitary standard of purity,
which is not more than i part per mil.
lion, aud this is ten times less than
.00000l, the limit of the test. Conse.
-, Tor nfos, tnO ,nl,
ammonia and not show the reaction. To
obviate this difficulty, a simple process
of distillation must be employed.
Ii all the ammonia that ten volumes
of water contain could be collected in
one volume OF water, and the test ap.
piled to this, and a reaction occur, it is
evident that the water in question con.
tains at least Il part per million.
FOR CHLORINE.
To determine the approximate amount
of chlorine, it is necessary to prepare a
standard solution of salt.
Weigh, as carefully as possible, one
ounce avoirdupois of best table salt; dis.
solve it in eighteen ounces of clean rain
water. This solution will contain very
nearly grain of chlorine per drop. The
greatest care should be exercised in
dropping the fluid, since the size of the
drop varies so much. 1t should be drop.
ped from an ounce bottle, and the drop
allowed to form slowly.
Prepare very weak solution OF
nitrate of silver, by dissolving crystal,
not larger than a pea, in about one
ounce of pure rain water. There will
be hardly any risk of making this solu.
tion too weak. Also prepare solution
of chromate of potash; bi.chromate OF
potash will answer the purpose, il the
chromnte cannot be obtained. The
solution should be made in rain water.
The strength of it is not important.
APPLICATION OF THE TEST.
Pour four ounces of the water to be
tested into saucer, and add enough
chromate of potash solution to impart q
distinct yellow color; then add a drop
of the silver solution: a red color is
produced where the drop strikes, from
the formation of chromate of silver,
which is quickly destroyed if the water
contains much salt; continue to add the
solution drop by drop, counting the
drops, and stirring the water after each
additional drop, until the water assumes
d faint reddish tint, which will occur as
soon as oil the chlorine has been precip.
itated. Then pour four ounces OF clean
rain water into another saucer, add one
drop of the solution of salt, observ.
ing the precaution already given about
the size of the drop, and proceed as be.
"a A.Ix y,11n,har NJ
drops of the silver solution to produce
| reddish tint in this than were required
to produce it in the other case, the
water tested contains less than one grain
of chlorine per gallon, since l'32 grain
| in four ounces of water is at the rate oi
one grain in I2s fluid ounces, or one gal.
Ion. Ifmore drops of the silver solution
were added to the water than to the
| fluid used for comparison, 1T Is easy,
from the number OF drops added to the
latter, to estimate the chlorine in the
former. For example: suppose ten drops
of silver solution represent one grain Of
chlorine per gallon, and the water il
question requires thirteen drops, then i
contains l3 grain of chlorine per gallon
From this it will be seen that If the solu
ticn of nitrate of silver is sufficiently
weak, it is possible to estimate very
small quantities Of chlorine. providing
the quantity of salt in the fluid used TO
com parison be known. But on accoun
Of tho difficulties in the way of weigh
ing, measuring and dropping, nothin
but an approximation can be expecte
from the process.